refactor: complete US stock migration

- Data collector: Alpaca REST polling (replaces Binance WebSocket)
- Order executor: Alpaca submit_order (replaces ccxt)
- Claude stock screener: daily MOC candidate analysis
- Remove ccxt/websockets dependencies
- Default universe: AAPL, MSFT, GOOGL, AMZN, TSLA + 28 more
- 399 tests passing, lint clean

2 files changed, 3 insertions, 1 deletions

diff --git a/services/data-collector/src/data_collector/config.py b/services/data-collector/src/data_collector/config.py
index 4761013..dd430e6 100644
--- a/services/data-collector/src/data_collector/config.py
+++ b/services/data-collector/src/data_collector/config.py
@@ -1,4 +1,5 @@
 """Data Collector configuration."""
+
 from shared.config import Settings
 
 
diff --git a/services/data-collector/src/data_collector/main.py b/services/data-collector/src/data_collector/main.py
index 38f8759..b42b34c 100644
--- a/services/data-collector/src/data_collector/main.py
+++ b/services/data-collector/src/data_collector/main.py
@@ -1,9 +1,9 @@
 """Data Collector Service — fetches US stock data from Alpaca."""
+
 import asyncio
 
 from shared.alpaca import AlpacaClient
 from shared.broker import RedisBroker
-from shared.config import Settings
 from shared.db import Database
 from shared.events import CandleEvent
 from shared.healthcheck import HealthCheckServer
@@ -33,6 +33,7 @@ async def fetch_latest_bars(
                 bar = bars[-1]
                 from datetime import datetime
                 from decimal import Decimal
+
                 candle = Candle(
                     symbol=symbol,
                     timeframe=timeframe,